Expandable broadheads that utilize a rear deploying expandable blade structure that does not hang up or get stuck in a ferrule slot, while at the same time improving penetration capabilities as well as facilitating arrow removal after target penetration, are disclosed in co-pending U.S. patent application Ser. No. 13/998,888, the contents of which are fully incorporated herein by reference. These expandable broadheads avoid blade-to-blade interference as the blades deploy.
In certain expandable broadheads, a shock collar is used to restrain the blades during the flight of the expandable broadhead. Upon impact of the expandable broadhead into a target, a portion of the shock collar breaks free, allowing the blades to deploy outwardly and expanding the total cutting surface of the expandable broadhead. This deployed impact configuration allows the expandable broadhead to create a larger entrance hole in the surface of a target, while the restrained in-flight configuration ensures maximum aerodynamic accuracy during flight. Shock collars for expandable broadheads are disclosed in U.S. Pat. No. 8,758,176, the contents of which are also fully incorporated herein by reference. The shock collars described in the U.S. Pat. No. 8,758,176 patent contain the blades of an expandable during flight, ensuring the broadhead's stability.
While these existing shock collars, as shown in 100 of FIG. 1, are effective for expandable broadheads having two deployable blades, there remains a need for lightweight, reliable shock collars for expandable broadheads having three or more deployable blades. Such shock collars should retain the deployable blades of the expandable broadhead during flight to maximize the accuracy of an arrow, while at the same time ensuring that an archer can rely on the collar to break on impact, allowing the blades to deploy upon impact into a target.
Furthermore, weight is a consideration when designing broadheads. The ferrules of existing broadhead designs are essential in centering those broadheads within the insert of an arrow, ensuring aerodynamic stability during flight. However, these ferrules are typically made of dense, heavy materials such as steel. Lightweight broadhead collars that could effectively center a ferrule within an arrow insert, while at the same time allowing the dimensions of the ferrule to shrink, would allow broadhead designers to add weight to different locations of the broadhead, achieving greater strength, durability, and cutting performance than was previously possible. Additionally, lightweight broadhead collars made of deformable materials could allow an interference fit between a ferrule, collar, and arrow insert, resulting in the centering of an broadhead within an arrow insert to promote in-flight performance and accuracy.